childhood obesity prevention programs: comparative ...childhood obesity prevention programs:...
TRANSCRIPT
Childhood Obesity Prevention Programs:
Comparative Effectiveness
Presented by Youfa Wang, MD, PhD, MS
Professor and Chair
Department of Epidemiology and Environmental Health
School of Public Health and Health Professions
University at Buffalo, the State University of New York (SUNY)
Outline of What to Expect
• Definitions, incidence, and prevalence of childhood obesity
• Grading the strength of a body of evidence
• Clinical questions addressed
• What was found
• What was learned about interventions to prevent childhood obesity
• How to use these findings
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AHRQ Comparative Effectiveness Review
Process
3
Topic Nomination
Peer Review Public
Comment
Systematic Review
Meta Analysis
Expert Input
Final AHRQ report, Clinician Summaries, and Consumer
Research Summaries
Learning Objectives
• Identify types of obesity prevention programs.
• Discuss the evidence on the effectiveness and
safety of prevention programs.
• Identify limitations in the current evidence base
related to interventions addressing childhood
obesity.
• Summarize future research directions such as
additional studies, study design, and analyses.
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Prevalence of Childhood Obesity
0
2
4
6
8
10
12
14
16
18
20
2 – 5 years 6 – 11 years 12 – 19 years
Pro
po
rtio
n o
bese
Age of Children
Prevalence in the US by age: 1976-1980 to 2009-2010
1976 –1980
2009 – 2010
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Health Consequences of Childhood
Obesity
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Obese children
Adverse health conditions
Cardiovascular outcomes
Psychosocial outcomes
Eating disorders
Depression Low
self-esteem
Metabolic outcomes
Biological Basis for Obesity
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Individual/Biological
Susceptibility
Dietary & Physical Activity
Patterns
Body Fat Stores
Energy Regulation
In Out
Factors Affecting Childhood
Obesity
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Individual examples
• Genetics
• Nutrition knowledge
• Nutrition attitude
• Body weight image
Home examples
• Parenting
• Home diet
• Parental weight status
School examples
• Nutrition service
• Curriculum
• Annual BMI
Community examples
• Sidewalks
• Parks
• Safety from traffic
• Crime rate
Regional and National examples
• Price of food
• Food assistance programs
Defining Obesity and Overweight
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• Different classifications
• Obesity in children:
► Medical condition in which excess body fat may have
adverse effect on health.
► ≥ age-sex-specific 95th percentile body mass index
(BMI).
• Overweight in children:
► ≥ age-sex-specific 85th percentile BMI, but < 95th
percentile.
Prevention vs Treatment
Prevention
• AKA “intervention”
• Goal: Prevent children from becoming overweight or obese
• May help overweight or obese children lose or stabilize weight
• Focus of this presentation
Treatment
• AKA “weight loss” or
“weight management”
• Goal: Weight loss among
pediatric patients.
• See AHRQ report Effectiveness of Weight
Management Interventions in
Children: a Targeted Systematic
Review for the USPSTF
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Analytic Framework: Evaluation of
Childhood Obesity Interventions
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Obesity-Related Clinical
Outcomes
Cardiovascular outcomes
Metabolic outcomes
Psychosocial outcomes
Settings
KQ1 – School
KQ2 – Home
KQ3 – Primary care
KQ 4 – Child care
KQ 5 – Community-level
KQ6 – Consumer health
informatics
KQ7 – Multi-setting
Adverse Effects of Intervention
Burden of intervention
Eating disorders
Psychosocial outcomes
Impact on growth and development
Injury
Cost
Other adverse events
All children age
2-18 years
Primary Outcomes
Change in overweight and obese status
Prevalence of overweight and obese
BMI
Other adiposity measures
Intermediate Outcomes
Nutrition knowledge, attitudes, beliefs
Food purchasing behaviors
Dietary intake
Food access
Physical activity
Sedentary behavior
Scope of the Review
Population Children 2-18 years old, regardless of BMI
Interventions a) Diet, physical activity, or combination of diet and physical activity
b) Setting of intervention
Comparators No intervention, usual care, or other intervention
Outcomes
a) Primary: Weight-related outcomes (e.g., BMI, obesity or
overweight rates)
b) Intermediate: Dietary intake (e.g., fruits and vegetables, sugar-
sweetened beverages), physical activity, sedentary activity
c) Adverse effects: Eating disorders, psychosocial outcomes, impact
on growth and development, injury, cost
d) Obesity-related clinical outcomes: Cardiovascular and metabolic
outcomes (e.g., blood pressure, blood lipids, blood glucose)
Timing a) ≥ 6 months for school-based interventions
b) ≥ 1 year for any other interventions
Settings School, home, primary care clinic, childcare, community,
environmental-level interventions, or any combination of settings
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Literature Search, Data Collection,
and Analysis
• Data sources: ► MEDLINE®, Embase®, PsycInfo®, CINAHL®,
Clinicaltrials.gov, and the Cochrane Library through August 11, 2012.
• Study inclusion criteria ► Randomized controlled trials, quasi-experimental studies,
or natural experiments conducted in high-income countries.
• Study screening & data extraction: ► Two reviewers independently reviewed each article for
eligibility.
► For each study, one reviewer extracted the data and a second reviewer verified the accuracy.
• Meta-analysis
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Key Questions
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KQ 1 What is the comparative effectiveness of school-based
interventions for the prevention of obesity or overweight in children?
KQ 2 What is the comparative effectiveness of home-based interventions
for the prevention of obesity or overweight in children?
KQ 3 What is the comparative effectiveness of primary care–based
interventions for the prevention of obesity or overweight in children?
KQ 4 What is the comparative effectiveness of childcare setting–based
interventions for the prevention of obesity or overweight in children?
KQ 5 What is the comparative effectiveness of community-based or
environmental-level interventions for the prevention of obesity or
overweight in children?
KQ 6 What is the comparative effectiveness of consumer health
informatics applications for the prevention of obesity or overweight
in children?
KQ 7 What is the comparative effectiveness of multi-setting interventions
for the prevention of obesity or overweight in children?
Studies Addressing the Key
Questions
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104 studies 6 studies 1 study
4 studies 9 studies 0 studies
Studies in multi-settings were presented under other KQs.
Strength of the Evidence
• Further research is very unlikely to change the confidence in the estimate of effect. High
• Further research may change the confidence in the estimate of effect and may change the estimate.
Moderate
• Further research is likely to change the confidence in the estimate of effect and is likely to change the estimate.
Low
• Evidence either is unavailable or does not permit estimation of an effect. Insufficient
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School-Based Interventions
• School as primary setting:
► Change in quantity of food
► Change in nutritional quality of food
► Increased physical activity
► Promotion of walk-to-school
► Combination of the above with home or community
interventions
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School-Based Interventions
• Dietary interventions:
► Decrease in BMI or BMI Z-score
measures
Strength of Evidence: Moderate
• Physical activity interventions:
► Impact on BMI, waist
circumference (girls), skinfold
thickness, percentage body fat
Strength of Evidence: Moderate
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School-Based Interventions
• Diet and physical activity
combined intervention and
weight-related outcomes:
► Reduced BMI, BMI Z-score,
prevalence of obesity and
overweight, percentage of
body fat, waist circumference,
and skinfold thickness
Strength of Evidence: Insufficient
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School-Based Interventions: Change in BMI
Meta-Analysis: Change in BMI between Control and Combined Diet and Physical Activity Groups in School-Only Settings
School-Based + Home Components
• Dietary interventions:
► Effect on preventing obesity
unknown
Strength of Evidence: Insufficient
• Physical activity interventions:
► Improvement in BMI, waist
circumference, and skinfold
thickness
Strength of Evidence: High
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School-Based + Home Components
• Diet and physical activity
combined interventions:
► Improvement in BMI, BMI
percentile, prevalence of
overweight or obesity
Strength of Evidence: Moderate
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School-Based + Home
Components: Change in BMI
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Meta-Analysis: Change in BMI between Control and Combined Diet
and Physical Activity Interventions in a School Setting with a Home
Component
School-Based Intervention + Home
+ Community Components
• Combination diet and physical activity
interventions:
► Improvement in weight outcomes
Strength of Evidence: High
• Physical activity interventions:
► Effect on preventing obesity unknown
Strength of Evidence: Insufficient
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School-Based Intervention +
Community Component
• Dietary interventions:
► Improved BMI and prevalence of overweight and obesity
Strength of Evidence: Insufficient
• Physical activity interventions:
► No difference in weight-related outcomes
Strength of Evidence: Insufficient
• Combination diet and physical activity interventions:
► Nonsignificant improvements in weight outcomes
Strength of Evidence: Moderate
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Home-Based Interventions
• Dietary interventions:
► No difference in BMI, fat mass, or weight
Strength of Evidence: Insufficient
• Combination diet and physical activity
interventions:
► No difference in weight outcomes
Strength of Evidence: Low
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Childcare Center Interventions
• Physical activity interventions:
► May improve BMI and percent body fat
Strength of Evidence: Insufficient
• Combination diet and physical activity
interventions:
► No difference in weight outcomes
Strength of Evidence: Low
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Community-Based or
Environmental-Level Interventions
• Combination of diet and physical activity interventions: ► Community + school involvement resulted in a
beneficial effect on preventing obesity
Strength of Evidence: Moderate
• Diet, physical activity, or combination of interventions: ► Community level alone or other settings – ability to
prevent obesity unknown
Strength of Evidence: Insufficient
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Conclusions & Discussion
• School-based interventions:
► Moderate evidence of effectiveness
• School-based physical activity with family
component or combined interventions in school with
home and community components:
► Most evidence for effectiveness
• Interventions conducted as environmental strategies,
consumer health informatics strategies, or testing
policies:
► Lack of evidence to determine impact on preventing obesity
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Summary of Key Evidence
Setting Intervention Measure Result Strength of Evidence
School-Based Diet BMI BMI Z-score
Improved Moderate
School-Based Physical activity
BMI Waist circumference (girls) Skinfold thickness % body fat
Improved Moderate
School-Based + Home
Physical activity BMI Waist circumference Skinfold thickness
Improved High
School-Based + Home
Diet + physical activity
BMI BMI percentile Prevalence of obesity or overweight
Improved Moderate
School-Based + Community
Diet + physical activity
BMI BMI Z-score
Improved Moderate
School-Based + Home + Community
Diet + physical activity
Weight outcomes Improved High
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Limitations of the Evidence Base
• Lack of studies in clinical settings
• Limited evidence testing environmental-based
or policy interventions
• Insufficient evidence on the effect of consumer
health informatics
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Gaps in the Evidence
• Need for greater understanding of contextual
factors associated with implementation
► Allow decision makers a better idea of applicability of
any given intervention
• Need for subgroup analyses by:
► Sex, age, race/ethnicity, socioeconomic status
• Need for additional evaluations of adolescents
► Obesity among adolescents more predictive of obesity
during adulthood
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Applicability of the Results
• Children in high-income countries ► May not be applicable to children in middle- and low-
income countries
• Studies with subgroup analysis ► Applicability to very young children and select
racial/ethnic groups unknown
• Age of studies ► Older studies may not be as effective in current
populations
• Setting of studies ► Focus on RCTs may understate interventions in non-
school settings
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What to Discuss with Patients
Concerns about childhood obesity and the
patient’s welfare
Patient’s BMI and how to diagnose overweight
and obesity in children
Factors contributing to overweight/obesity in
children:
Less physical activity
More sedentary/screen time
High calories, too much unhealthy food
Inappropriate use of food rewards
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What to Discuss with Patients
Appropriate food serving size
Monitoring total daily caloric intake
What can be done at home
Health consequences of obesity in children
Effectiveness of obesity prevention interventions
Community or school obesity prevention
programs
What to do if healthy food or safe physical
activity locations are not accessible
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Continuing Education Credit
• To obtain credit:
► Complete the online evaluation.
► Pass the posttest with a grade of 80% or higher.
If you have any problems receiving certification, please
contact:
Postgraduate Institute for Medicine
304 Inverness Way South, Suite 100
Englewood, Colorado 80112
Phone: (303) 799-1930
Fax: (303) 858-8848
Email: [email protected]
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Acknowledgements
• Research team: Youfa Wang (PI), Yang Wu
(Coordinator), Jodi Segal (Task Leader), Li Cai,
Renee F. Wilson (Project Manager), Christine
Weston, Oluwakemi Fawole, Sara Bleich,
Lawrence J. Cheskin, Nakiya N. Showell,
Brandyn Lau, Dorothy T. Chiu, Allen Zhang
• Reviewers and experts who contributed to the
project
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